Certification of Plants Producing Unbonded Single Strand Tendons (Process Certification)

Launched in 1989, the Post-Tensioning Institute (PTI) program for Certification of Plants Producing Unbonded Single Strand Tendons has been developed to provide independent certification of a plant's extrusion and/or fabrication process and its capability to produce standard and/or encapsulated unbonded single strand tendons. This certification program also includes evaluation of calibration practices for jacks and gauges used for stressing single strand tendons. The program is applicable to all facilities whether fixed or mobile.

The certification of a plant under this program indicates that the plant and the personnel are capable of producing unbonded single strand tendons in conformance with the Post-Tensioning Institute's Specification for Unbonded Single Strand Tendons. The certification program extends only to the process for extrusion and/or fabrication procedures and materials within the examined plant, and is expressly not intended to cover procedures or events subsequent to shipment of tendons to the job site.

PTI Certified Plants and Certification Actions

Click here for the current list of PTI Certified Plants. The latest certification actions are listed in the pdf list of PTI Certified Plants on the right side of the page.

Program Requirements

The procedures and requirements of the PTI Unbonded Tendon Plant Certification Program are set forth in the following documents:

Manual for Certification of Plants Producing Unbonded Single Strand Tendons (PTI-CRT20 G1-0817)

Sets forth the procedures, and administrative and technical requirements for plant certification.


PTI Quality Management System Manual (PTI-CRT20 G2-1015)

Documents PTI's quality system and sets forth procedures and requirements for the operation and administration of the UTPC program.


Nonconformity Action Plan Template (PTI-CRT20 F30-1013)

Template provided for plants to report their Nonconformity Action Plan.

Unbonded Tendon Plant Certification Committee

The CRT-20: Unbonded Tendon Plant Certification Committee (UTPC Committee) is the management group that is responsible for decisions relating to the granting, maintaining, extending, suspending, and withdrawing of certification for facilities that fabricate unbonded single strand post-tensioning tendons